Material copied from the St. Francis Mission website, referencing information about the Buechel Memorial Lakota Museum.
..."At the same time, low brace heights can result in the string smacking the archer’s wrist. A little practice and skill can prevent that from happening, and as Standing Bear’s autobiography tells us, young boys dedicated a lot of time to develop their skills. Also, holding a bow more horizontally helps keep the wrist out of the way, allowing for a lower brace height. Drawings of strung bows that appear in winter counts and ledger art generally show bows with a low brace height.
A hand guard, called napakaha in Lakota, made from female elk hide or buckskin, was tied over the left hand behind the thumb to protect it while shooting. The collection has two, one was obtained from Mrs. Little Cloud in 1915. Even then, according to Father Buechel’s notes, it was quite old. The other, smaller in size, was made by John Red Feather. "
http://www.sfmission.org/museum/archive/images/bmlm_739.jpg http://www.sfmission.org/museum/archive/images/bmlm_740.jpg Or you could twist up the string some and raise the brace height...
Killdeer :D